Pump and valve assembly



PUMP AND VALVE ASSEMBLY Filed March 14, 1941 '2 Sheets-Sheet 1 INVENTOR:

ATTORNEYS.

Jan. 26, 1943. E. F. JIRSA PUMP AND VALVE ASSEMBLY Filed March 14, 19412 Sheets-Sheet 2 FIG. 2"

INVENTOR A EM'IL F. JIRSA FIG. 3

Patented Jan. 26, 1943 UNITED STATES PATENT OFFICE PUMP AND VALVEASSEMBLY Emil F. Jirsa, Waterloo, Iowa, assignor to John Deere TractorCompany, Waterloo, Iowa, a corporation of Iowa 6 Claims.

The present invention relates generally to pump and valve assemblies,with particular reference to those used in lubricating systems forinternal combustion engines and the like, although I-do not intend myinvention to be limited to this particular use.

Lubricating oil pumps are usually of the constant displacement type,such as gear pumps or the like, and are provided with a pressurereservoir or header into which lubricating oil is pumped under pressureand from there distributed to various parts of the engine. The pressurein the reservoir or header is maintained constant by supplying to thereservoir an excess quantity of oil and providing a relief valve, backedby a spring set at a definite pressure. As the demand for oil from theheader fluctuates, the spring-backed valve permits a greater or lesserquantity of oil to escape, and thus holding the pressure in the headersubstantially constant.

The relief valve usually takes the form of an annular seat through whichoil can flow from the header under control of a leaf spring valveclosure member or spring loaded ball adapted to cover the annular seat,but yieldable to pressure of the oil within the header. In the eventthat a small grain of carbon or grit becomes lodged under the valveclosure spring or ball at a time when there is a heavy demand for oil,the valve cannot completely close, with the result that the pressure inthe header decreases so that insufficient oil is supplied to thebearings. Occasionally it is necessary to disconnect the pump and removeit from the crank case of the engine for the purpose of cleaning thegrit out from under the valve spring.

It is the principal object of this invention, therefore, to provide avalve which is entirely self-cleaning and prevents the valve from beingheld open for any appreciable length of time by a. piece of carbon orgrit.

A further object of my invention relates to the provision of a simple,compact and inexpensive pump and valve arrangement embodying theself-cleaning feature.

These and other objects and advantages of my invention will be apparentafter a consideration of the following description in which reference ishad to the drawings appended hereto, in which Figure l is a sectionalelevational view taken along a center line of a lubricating pump andvalve unit embodying the principles of the present invention, asindicated by a line 1-1 in Figure Figure 2 is a sectional plan viewtaken along a line 2-2 in Figure 1; and

Figure 3 is a sectional elevational view taken along a line 3-3 inFigure l and Figure 2.

Referring now to the drawings, the lubricating pump and valve unitcomprises a unitary housing 5 disposed in a generally vertical positionin the lower part of a crank case 6 of an internal combustion engine.The crank case 6 is apertured at l in the bottom thereof to receive thehousing 5, the latter being provided with a circumferentially extendingflange 8 which bears against the bottom of the crank case 6 and isbolted thereto by means of bolts ii. A gasket [0 is provided under theflange 8 to prevent leakage of oil from the crank case.

The housing 5 is generally tubular in form Q and has a cylindrical upperportion I2 adapted to be received within an aperture [3 in a bracket I lformed integrally with the crank case 6, and thus the housing is rigidlyheld within the crank case.

lihe lower end of the housing 5 is provided with a pump chamber l5,within which are fitted a pair of intermeshing gears [6, ll,constituting a gear pump of the conventional constant displacement type.The gears l6, I! are rotated by means of a drive shaft [8 which extendsvertically through the housing 5 and projects from the upper end thereofand is connected with a drive gear 19 disposed in meshing arrangementwith a suitable driving Worm 20, from which power is obtained from theinternal combustion engine for driving the pump. The pump chamber 15 isclosed by a cover plate 2|, removably attached to the lower end of thehousing 5 by bolts 22, thus providing easy access to the gears.

Oil is supplied to the pump through an intake passage 25 formed in thelower part of the housing, and is carried by the teeth of the gears I6,I? wound the circumference of the pump chamber 15 in well-known mannerand is discharged through a discharge duct 25 to which is connected aconduit 21 extending vertically from the discharge duct 26. The conduit21 is connected by means of a fitting 28 in communication with a highpressure reservoir or header 29 within the housing 5, and from thereservoir 29 the oil is led through supply ducts 30, which are connectedin communication with the reservoir, to various bearings in the internalcombustion engine. Oil is also forced through a duct 3! from thereservoir 29 to a suitable oil filter (not shown), from which the oil isreturned to a fitting 32 (see Figure 3), into the top of a screenedintake enclosure 34 which protects the intake duct 25 from the largerpieces of carbon and grit which may be in the bottom of the crank case.

Coming now to that part of the structure with which my invention is moreparticularly concerned, the pump gear I! is provided with a shaft 35which is fixed thereto and rotatable therewith. The shaft is journaledin a bearing portion 35 in the housing and extends upwardly through ahorizontally extending passage 31 at one side of the lower end of theresvoir chamber 29 and disposed in communication therewith, and theupper end of the shaft 35 projects outwardly of the housing 5 and isjournaled in a second bearing portion 33 in the housing. The upper endof the shaft 35 is provided with an axially extending recess 33connected in communication with the passage Si by means of a pluralityof apertures 4%! in the shaft 55. The recess 39 defines an annular valveseat 45 at the upper end of the shaft 35.

A leaf spring valve closure member 45 is dis posed in engagement withthe annular valve seat 4|, and extends horizontally to a supporting bolt46 by means of which the leaf spring closure member 45 is supported atits opposite end on a lug 41 extending outwardly from the housing 5. Theclosure member 45 is biased toward seating engagement with the annularseat 4i, not only by the elasticity in the leaf spring 45 itself but bymeans of a coiled compression spring 49, which bears against the upperside of the leaf spring 45 and extends upwardly therefrom and reactsagainst the lower end of a set screw 55, which is threadably engagedwithin a threaded aperture 5| in a lug portion 52 extending outwardlyand forming an integral part of the housing 5. A. centering core 53 isattached to the leaf spring 45; for holding the lower end of the coilspring 49 in proper position against the valve closure, and has a shortstem 54 extending downwardly through a suitable aperture in the valveclosure 45. By turning the set screw 59, the force of the compressionspring 49 can be increased or decreased, to adjust the pressure of theclosure member 45 against the valve seat 4|, and thus to adjust thepressure which will be maintained within the reservoir 29. The set screwhill is secured in adjusted position by means of a bracket 55' engagingthe head of the set screw 55) and supported by a pair of bolts 55attached to the side of the housing 5.

With the pressure. of the spring 49 set at a predetermined value, aslong as there is an excess of oil flowing through the discharge duct 27of the pump into the reservoir 29, there is a flow of oil through theapertures 4b and the recess 39 out through the annular valve seat 4funder the valve closure 45, the pressure of oil being sufiicient toforce the leaf spring 45 away from seating engagement with the valveseat 4!. If the oil pressure in the reservoir 29 drops below thepredetermined value at which the spring 49 is set, the latter forces theclosure 45 against the Valve seat and prevents further escape of oilthrough therelief valve until the pressure within the chamber 29 risesonce more to the predetermined value.

Since the shaft 35 is rigidly connected to the gear ll, it rotatestherewith and thus causes the annular valve seat to rotate relative tothe leafvspring 45!. This-rotationis continuous as long as the pump isoperating and produces a grinding action between the valve seat andvalve closure which readily dislodges any particles of grit or carbonthat may tend to lodge therebetween.

A slightly more aggressive wiping action of the valve seat 4| again-stthe closure 45 can be produced, if so desired, by offsetting the recess39 slightly with respect to the axis of rotation of the shaft 35.

I do not intend my invention to be limited to the details shown anddescribed in connection with this embodiment, except as limited by theclaims which follow.

I claim:

1. In combination, a housing, a valve seat member journaled for rotationin said housing and having a recess therein disposed in communicationwith the interior of said housing and defining a valve seat outside thelatter, a leaf spring closure member mounted outside said housing andbiased into seating engagement with said valve seat but movable awayfrom the latter to open the valve, and means for rotating said seatmember relative to said closure member.

2. In combination, a housing, a shaft journaled in said housing andprojecting outwardly thereof, said shaft having a recess in the outerend thereof disposed in communication with said housing and defining anannular valve seat at the end of the shaft, a leaf spring closure membermounted outside said housing and biased into seating engagement withsaid valve seat but movable away from the latter to open the valve, and

means for rotating said seat member relative to said closure member.

3. In combination, a housing including a pressure chamber, a valve seatmember journaled for rotation in said housing and having a recesstherein disposed in communication with said chamber and defining anannular valve seat outside the, latter, a closure member mountedadjacent said valve seat, yieldable means for biasing said closuremember toward seating engagement with said seat but permitting theclosure member to yield' to a predetermined pressure Within said chamberto open the valve, and means for rotating said valve seat memberrelative to said closure member.

i. In combination, a housing including a pressure chamber, a shaftjournaled in said housing and projecting outwardly thereof, said shafthaving a recess in the outer end thereof disposed in communication withsaid chamber, and defining an annular valve seat at the end of theshaft, a closure member mounted adjacent said valve seat, yieldablemeans for biasing said closure member toward seating engagement withsaid seat but permitting the closure'member to yield to a predeterminedpressure within said chamber to open the valve, and a gear pumpincluding a pair of intermeshing gears, one of said gears being attachedto said shaft to drive the same, means for driving the other gear, andduct means connecting the discharge side of said pump with said chamber.

5. In combination, a housing including a pressure chamber, a valve seatmember journaled' for rotationv in said housing and having a recesstherein disposed in communication with said chamber and defining anannular valve seat outside. the latter, a leaf spring closure membermounted outside said housing and biased into seating engagement withsaid valve seat but movable away from thelatterto open'the valve, and

means for rotating said seat member relative to said closure member,said last named means com-1' prising a gear pump including a pair ofinter meshing gears, one of said gears being attached to said shaft todrive the same, means for driving the other gear, and duct meansconnecting the discharge side of said pump with said chamber.

6 In combination, a housing including a pressure chamber, a shaftjournaled in said housing and projecting outwardly thereof, said shafthaving an axially extending passage therein from the outer end andcommunicating within the housing with said pressure chamber, an annularvalve seat at the outer end of said shaft, a closure member adapted tocooperate with said valve seat but movable away from the latter to openthe valve, spring means for biasing said closure member toward seatingengagement with said seat but permitting the closure member to yield toa predetermined pressure within said chamber to open the valve, andmeans for rotating said shaft relative to said closure member.

EMIL F. JIRSA.

